1. Field of the Invention
The present invention relates to a three-dimensional observation system which allows the three-dimensional viewing of observation sites inside body cavities by means of an endoscope.
2. Description of the Related Art
Three-dimensional observation systems which allow the observation of three-dimensional images by picking up two images that have a parallax, and respectively guiding these captured images to the left and right eyes of an observer, have been known in the past.
Such three-dimensional observation systems have also attracted attention in the medical field, and surgical procedures using so-called three-dimensional endoscopes, in which this technique is applied to an endoscope, are becoming more widespread.
Meanwhile, fine surgical manipulation skill is required in surgical procedures that are performed while picking up the image of an observation site by means of an endoscope inserted into a body cavity and observing this endoscopic image; however, in the case of surgical procedures using a three-dimensional endoscope, delicate treatments that depend on a high degree of manipulation skill can be performed with greater assurance than in cases where surgical procedures are performed while observing a conventional two-dimensional endoscopic image.
In such a three-dimensional observation system, three-dimensional observation is generally made possible using a binocular system by picking up two images that have a parallax with respect to the object of observation, and respectively guiding these two captured images to the left and right eyes of the observer.
For example, devices in which two images are alternately displayed on a monitor screen that displays captured images, and these images are observed via viewing glasses equipped with a liquid crystal shutter that is synchronized with the switching of this display, and devices in which the direction of polarization of two images is varied, and the images are viewed via polarized viewing glasses that have different polarization directions for the left and right eyes and the like are known as display devices used to guide two such images that have a parallax to the eyes of the observer.
Meanwhile, in surgical procedures using an endoscope, the operating surgeon performing the procedure must perform an extremely delicate surgical manipulation while observing the endoscopic image, and it is important to alleviate the fatigue felt by the operating surgeon in realizing this delicate surgical manipulation.
Generally, in surgical procedures using endoscopic images, the images captured by the endoscope are displayed on a monitor placed inside the operating room. The surgical procedure is performed while viewing the operating site on the endoscopic image displayed on this monitor, and the operating instrument operated by the operating surgeon himself. In this case, the operating surgeon must work while directing his body toward the operating site on the patient undergoing the surgical procedure, and directing only his face toward the monitor. As a result, the operating surgeon is forced to adopt an unreasonable posture, so that fatigue tends to occur. In order to prevent the occurrence of such fatigue, it is desirable that the operating surgeon be able to observe the monitor screen while directing his face toward the front (a direction in which the operating surgeon views the operating site while facing the patient).
Furthermore, in order to perform the surgical procedure smoothly in addition to alleviating fatigue of the operating surgeon, numerous persons cooperating in the surgical procedure such as assistants that assist in the surgical procedure, anesthesiologists, nurses and the like are also involved, and it is necessary to perform the operation with the cooperation of these various cooperating persons. Accordingly, it is important that the operating surgeon himself be able to ascertain the status of the cooperating persons that surround the operating surgeon, and it is also necessary that the cooperating persons be able to grasp the surgical procedure being performed by the operating surgeon.
However, in cases where the viewing glasses equipped with a liquid crystal shutter or polarized viewing glasses are used in a surgical procedure that is performed while viewing a three-dimensional image, the monitor that displays this image is usually disposed in a position that is apart from observers such as the operating surgeon, cooperating persons and the like inside the operating room, so that the observers must constantly turn their faces toward the monitor when observing the three-dimensional image. This forces the observers into a posture that causes fatigue. Furthermore, the operating surgeon must ascertain the status of surrounding cooperating persons via the polarized viewing glasses or viewing glasses equipped with a liquid crystal shutter, so that it is difficult for the operating surgeon himself to ascertain the status of surrounding persons, and so that it is also difficult for the surrounding cooperating persons to ascertain the status of the operating surgeon.
Furthermore, in cases where the image that is observed is a three-dimensional image, the fatigue of the operating surgeon is also affected by the direction of the parallax. For example, in the image pickup device used for three-dimensional observation, two images that have a parallax in a certain direction are respectively viewed by the left and right eyes of the operating surgeon, so that a three-dimensional image is recognized. However, in cases where the parallax direction of the three-dimensional image viewed by the operating surgeon and the parallax direction of the operating surgeon are different, it is difficult to grasp the positional relationship between the orientation of the three-dimensional image and the orientation of the surgical operating instrument operated by the operating surgeon himself. This may cause the operating surgeon to become confused; as a result, the operating surgeon may suffer from fatigue.
As a display device for three-dimensional captured images that alleviates such fatigue of the operating surgeon and makes it easy to grasp surrounding conditions, a head-mounted display device, which has a monitor that displays two captured images and in which an optical system that guides the images displayed on this monitor to the eyes of the observer, has also been proposed (for example, see Japanese Patent Application Laid-Open No. 8-194172).
This head-mounted display device is mounted on the head of the operating surgeon; furthermore, switching means that allow the passage of external light to the monitor that displays the captured images, or that cut off such external light, are provided, so that the operating surgeon can visually recognize both three-dimensional captured images and the surrounding conditions by a switching operation between the passage and blocking of external light using the switching means.
The present invention provides a three-dimensional observation system used to perform surgical procedures while observing three-dimensional images, which makes it possible to perform fine surgical procedures while alleviating fatigue of the operating surgeon, and which also allows other persons cooperating in the surgical procedure to confirm images on the monitor observed by the operating surgeon, and thus facilitates mutual understanding between the operating surgeon and persons cooperating in the surgical procedure.